Small ponds have outsized impact on global warming: study

Tiny natural ponds pose an overlooked danger for speeding up global warming, according to a study published Monday in the journal Nature Climate Change.In experiments designed to simulate moderate future warming, scientists in Britain found that such ponds -- a metre (three feet) across -- gradually lose the capacity to soak up one kind of greenhouse gas and give off even more of another.After seven years at higher-than-ambient temperatures, "the ability of the ponds to absorb carbon dioxide was